1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there
2、from, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions. Copyright 2014 SAE International All rights reserved. No part of this p
3、ublication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-497
4、0 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/AIR6112 AEROSPACE INFORMATION REPORT AIR6112 Issued 2014-12 A Guideline for Aeros
5、pace Platform Fiber Optic Expanded Beam Interconnect Technology RATIONALE Expanded beam (EB) technology offers the aerospace fiber optic industry operational advantages over physical contact optical interfaces to include: greater tolerance to particulate contamination, ease of cleaning, protection o
6、f the optical fiber core, capability for non-physically contacting optical interface, and lower mating forces. 1. SCOPE This SAE Aerospace Information Report (AIR) provides an overview of EB technology as it applies to the aerospace fiber optic industry. Applicable personnel include: Managers Engine
7、ers Technicians Logisticians Trainers/Instructors Third Party Maintenance Agencies Quality Assurance 1.1 Purpose The purpose of this document is to provide an overview of EB technology for aerospace applications. SAE INTERNATIONAL AIR6112 Page 2 of 9 2. REFERENCES 2.1 Applicable Documents The follow
8、ing publications form a part of this document to the extent specified herein. The latest issue of SAE publications shall apply. The applicable issue of other publications shall be the issue in effect on the date of the purchase order. In the event of conflict between the text of this document and re
9、ferences cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001,
10、Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. ARP5061 Guidelines for Testing and Support of Aerospace, Fiber Optic, Inter-Connect Systems AS5590 Connectors, Fiber Optic, Advanced, Circular or Rectangular, Plug and Receptacle, Environment Resistant, Removable T
11、ermini/Contacts, General Specification For ARP5602 A Guideline for Aerospace Platform Fiber Optic Training and Awareness Education AS5675 Characterization and Requirements for New Aerospace Fiber Optic Cable Assemblies - Jumpers, End Face Geometry, Link Loss Measurement, and Inspection AIR6031 Fiber
12、 Optic Cleaning 2.1.2 U.S. Government Publications Copies of these documents are available online at http:/quicksearch.dla.mil. FED-STD-1037 Glossary of Telecommunications Terms MIL-PRF-29504 TERMINI, FIBER OPTIC CONNECTOR, REMOVABLE, GENERAL SPECIFICATION FOR MIL-PRF-29504/4 TERMINI, FIBER OPTIC, C
13、ONNECTOR, REMOVABLE, ENVIRONMENTAL RESISTING, PIN TERMINUS, SIZE 16, REAR RELEASE, MIL-DTL-38999, SERIES III MIL-PRF-29504/5 TERMINI, FIBER OPTIC, CONNECTOR, REMOVABLE, ENVIRONMENTAL RESISTING, SOCKET TERMINUS, SIZE 16, REAR RELEASE, MIL-DTL-38999, SERIES III MIL-PRF-29504/18 TERMINI, FIBER OPTIC, C
14、ONNECTOR, REMOVABLE, ENVIRONMENTAL RESISTING, GENDERLESS TERMINUS, REAR RELEASE, CERAMIC FERRULE, 1.25 MM FERRULE (FOR MIL-PRF-64266 CONNECTORS) MIL-DTL-38999 CONNECTORS, ELECTRICAL, CIRCULAR, MINIATURE, HIGH DENSITY, QUICK DISCONNECT (BAYONET, THREADED, AND BREECH COUPLING), ENVIRONMENTAL RESISTANT
15、, REMOVABLE CRIMP AND HERMETIC SOLDER CONTACTS GENERAL SPECIFICATION FOR MIL-DTL-83526 CONNECTORS, FIBER OPTIC, CIRCULAR, ENVIRONMENTAL RESISTANT, HERMAPHRODITIC, GENERAL SPECIFICATION FOR MIL-DTL-83526/20 CONNECTOR, FIBER OPTIC PLUG, CIRCULAR HERMAPHRODITIC, IN-LINE MOUNT, 2 AND 4 POSITIONS, EXPAND
16、ED BEAM MIL-DTL-83526/21 CONNECTOR, FIBER OPTIC, CIRCULAR HERMAPHRODITIC, BULKHEAD, LOW PROFILE WITHOUT STRAIN RELIEF, JAM-NUT MOUNT, 2 AND 4 POSITIONS, EXPANDED BEAM SAE INTERNATIONAL AIR6112 Page 3 of 9 2.2 Related Publications The following publications are provided for information purposes only
17、and are not a required part of this SAE Aerospace Technical Report. 2.2.1 ANSI Publications Available from American National Standards Institute, 25 West 43rd Street, 4th Floor, New York, NY 10036, Tel: 212-642-4900, www.ansi.org. ANSI Z136.1-2007 American National Standard for Safe Use of Lasers AN
18、SI Z136.2-1997 American National Standard for the Safe Use of Optical Fiber Communication Systems Utilizing Laser Diode and LED Sources ANSI/TIA-440-B-2004 Fiber Optic Terminology 2.2.2 IEC Publications Available from IEC Central Office, 3, rue de Varembe, P.O. Box 131, CH-1211 Geneva 20, Switzerlan
19、d, Tel: +41 22 919 02 11, www.iec.ch. IEC 60825-1 Laser Safety Equipment Classification (Safety of laser products) IEC 60825-2 Safety of Optical Fibre Communication Systems IEC 60825-4 Laser Guards 2.2.3 NASA Publications Available from NASA, Documentation, Marshall Space Flight Center, AL 35812, ww
20、w.nas.nasa.gov. NASA-STD-8739.5 Fiber Optic Terminations, Cable Assemblies, and Installation 2.2.4 NAVAIR Publications Commanding Officer, Naval Air technical Data and Engineering Service Command, Naval Air Station, North Island, P.O. Box 357031, Building 90, Distribution, San Diego, CA 92135-7031.
21、NAVAIR 01-1A-505.4 INSTALLATION AND TESTING PRACTICES AIRCRAFT FIBER OPTIC CABLING 2.2.5 ARINC Publications Available from ARINC, 2551 Riva Road, Annapolis, MD 21401-7435, Tel: 410-266-4000, . ARINC Specification 801 Fiber Optic Connectors ARINC Report 805 Fiber Optic Test Procedures ARINC Report 80
22、6 Fiber Optic Installation and Maintenance SAE INTERNATIONAL AIR6112 Page 4 of 9 2.2.6 Other Applicable References EN 2591 Aerospace Series, Elements of Optical and Electrical Connection, Test Methods EN 3197 Aerospace Series, Installation of Electrical and Optical Interconnection Series Understandi
23、ng Fiber Optics, Jeff Hecht, ISBN 0-13-956145-5 Fiber Optics Installer and Technician Guide, Bill Woodward, ISBN 0-7821-4390-3 3. PRINCIPLES OF EXPANDED BEAM TECHNOLOGY This section describes basic EB components and their function. Detailed design information can be found in ARP6008. 3.1 In EB Techn
24、ology, the light beam exiting a launch fiber is expanded and collimated by a lens, and the light propagates through air to a second lens where it is focused down into the receiving fiber. The basic elements of a ball lensed expanded beam interconnect are shown in Figure 1 as an example. Figure 1 - B
25、asic elements of a ball lensed expanded beam interconnect 3.2 Key Components a. Fiber to Lens Alignment: The optical fiber is secured within a fiber holder. The holder may take different forms. The holder aligns the optical fiber with the lens to maximize the transfer of light. b. Lens: The function
26、 of the lens is to expand, collimate and focus the light from and into the fiber. There are different types of lens styles such as ball lens, GRIN (Graded Index) rod lens, plano-convex lens and so on. The size and material of the lens also varies depending on application and expanded beam technology
27、. c. Lens Holder: The lens is secured in a lens holder which there are various types. d. Optical Alignment: There are several ways of aligning EB assembly pairs. Two examples are: Alignment pins Alignment sleeves Both these methods are used today. Optical FiberLens Lens Holder Fiber HolderLight Beam
28、SAE INTERNATIONAL AIR6112 Page 5 of 9 e. AR Coating: Anti-reflective (AR) coatings are applied on the lenses and/or terminated fiber end faces to improve return loss and insertion loss. Coatings can also provide scratch resistance, Note that the AR coatings are generally wavelength specific and must
29、 be designed to meet system requirements. Further information can be found in ARP6008. 4. FEATURES OF EXPANDED BEAM TECHNOLOGY The aerospace industry has identified the following features of expanded beam technology. 4.1 Greater Tolerance to Particulate Contamination EB technology increases the surf
30、ace area of optical transmission. The larger surface area tolerates a high level of particulate contamination as shown in Figures 2 and 3. 4.2 Ease of Cleaning The cleaning of EB interfaces is inherently easier than that of a PC interface due to the larger surface area of the optical interface. Howe
31、ver, care should still be taken to ensure that particulates, fluids and fluid residues are removed. Refer to AIR6031 for additional information on cleaning. 4.3 Protection of the Optical Fiber Core In EB technology the optical fiber core is protected behind the lens. This eliminates the potential to
32、 damage the core during mating throughout the life of the interconnect by moving the optical interface to the face of the lens. 4.4 Capability for Non-Physically Contacting Optical Interface In EB technology the optical beam is expanded and typically transmitted across an air gap. This maintains con
33、sistent optical transmittance during repeated mating cycles. As an example M83526/20 and /21 connectors have undergone mating durability testing of over three thousand cycles with a max change in transmittance of 0.50 dB insertion loss as shown in Figure 4. 4.5 Lower Mating Forces Mating forces are
34、a concern in every interconnection. EB technology may offer lower mating force options over PC, especially in backplane applications, circuit card assemblies (CCA) and large single fiber channel count applications as shown in Figures 5 and 6. 5. NOTES 5.1 A change bar (l) located in the left margin
35、is for the convenience of the user in locating areas where technical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and
36、(R) are not used in original publications nor in documents that contain editorial changes only. SAE INTERNATIONAL AIR6112 Page 6 of 9 Figure 2 - Comparison of dust size to optical fiber diameters and expanded beam diameters (3 mm ball lens used as an example) Average Dust Particle 5 40 5 m 40 m Expa
37、nded Beam 400 m 600 m Fiber Core Sizes SM 9 m Core MM 50 m Core MM 62.5 m Core SAE INTERNATIONAL AIR6112 Page 7 of 9 Figure 3 - Comparison of butt-joint to expanded beam Beam Expansion Elements SAE INTERNATIONAL AIR6112 Page 8 of 9 . Figure 4 - Mating cycle durability graph Figure 5 - Examples of reduced force interconnects (VITA 66.3) SAE INTERNATIONAL AIR6112 Page 9 of 9 Figure 6 - 20 channel expanded beam connector assembly (MIL-DTL-38999 Series III) PREPARED BY SAE COMMITTEE AS-3, FIBER OPTICS AND APPLIED PHOTONICS
